1. Definitions
As used herein, the term "indexing" means the process of locating and aligning one component with another in precise, repeatable registration; e.g., the faceplate of a cathode ray tube with the tube funnel.
The term "indexing means" is the means used for registering one component with another.
The term "V-shaped groove" means a groove used in indexing, and shaped in cross-section similarly to a capital "V". The section of the groove not in contact with the associated ball; i.e., the bottom of the groove, may be rounded.
The term "register" or "registration" means the aligning or "indexing" of one component with another.
The term "angle" refers to the included or subtended angle of a V-groove used in indexing. It is also referred to as a "wedge angle."
2. Field of the Invention
This invention relates generally to means for the mechanical registration of one component with another. This invention is especially useful for precisely indexing the shadow mask or mask frame of a color cathode ray tube with other tube components, especially components in tubes having a tension foil shadow mask. The indexing means according to the invention may also be used for precisely indexing the shadow mask component of a color cathode ray tube with the associated faceplate during the photoscreening of phosphors on the faceplate.
3. Art
The following are being submitted to the Patent and Trademark office for evaluation as to their possible relevance to the claimed subject matter. It is believed to be the closest of the art available, but the applicants make no admission as to the fact of its being "prior art," to its relevance in fact, to its legal sufficiency, or to its priority in time, nor do applicants represent that no better art exists.
(a) Procedures in Experimental Physics. I. Strong et al. N.Y.: Prentice-Hall. 1938. Pp. 585-6. Description of kinematic designs for positioning various elements of an instrument. PA1 (b) "The CBS-Colortron: A Color Picture Tube of Advanced Design." N. Fyler et al. Proc. of the IRE. Jan, 1954. Dec. Class. R583.6. Pp. 326-334. A shadow mask has three projecting springs with V-grooves at the ends which are perpendicular to the tube axis. Glass studs projecting from the faceplate provide for receiving the V-grooves to align mask and faceplate. PA1 (c) U.S. Pat. No. 3,894,321 to Moore. (1) Alignment holes in the corners of a shadow mask mate with alignment nipples in a faceplate. The nipples pass through the holes to fit into funnel recesses. (2) For faceplate photo-screening, a mask is stretched on a frame, and the mask is registered with the faceplate by alignment holes in the mask which mate with alignment posts. (3) A frame supporting a shadow mask is held in registration by resting against alignment posts on a tilted bed. PA1 (d) U.S. Pat. No. 4,100,451 to Palac. Describes the suspension of a non-self-rigid domed shadow mask with respect to a faceplate by four suspension means which provide for coupling and indexing the mask directly to corner portions of the faceplate. In one embodiment the indexing means comprises legs having rounded portions which engage indexing cavities in the faceplate which may be in the form of V-grooves or slots. Another approach utilizes V-blocks at the four corners of the faceplate, each of which has a clamp attached to the mask, and each clamp has a foot for mating with a V-block. PA1 (e) U.S. Pat. No. 4,547,696 to Strauss. A tension mask supporting and registration system is disclosed in which balland-groove indexing means are utilized. PA1 (f) U.S. Pat. No. 2,961,560 to Fyler. A color picture tube is described in which a flat shadow mask is registered with a face panel by indexing means. PA1 (g) U.S. Pat. No. 2,733,366 to Grimm et al. A target assembly is disclosed for a color kinescope. A planar shadow mask is held in tension in a metal frame. The frame and the associated mask is held in registration with the faceplate and the phosphor pattern deposited on the faceplate. Means for registration and assembly of the frame and faceplate is indicated as comprising three metal support posts extending from the frame. The support posts have rounded metal terminations which are shown as being seated in respective cavities in the faceplate. PA1 1. The textbook description, Item (a), provides no instruction as to how various components of a cathode ray tube may be indexed for photoscreening and assembly, nor does it provide details of groove configurations and dimensions. PA1 2. The component-registration means disclosed by Moore and the others is considered to be too imprecise and impractical for the manufacture of a color cathode ray tube having a tension foil shadow mask. PA1 3. The disclosure of Grimm et al, Item (g), provides little detail of the registration means directly relevant to the present invention. PA1 4. The problem with which the present invention is concerned--ball hang up (or protuberance hang up) in indexing means--is not addressed. PA1 1. Providing an improvement in the means for precisely and repeatedly registering one component with another. PA1 2. Providing an improvement in the means for registering major components of a cathode ray tube with an internal shadow mask. PA1 3. Providing an improvement in cathode ray tube component indexing means, one that will facilitate manufacture. PA1 4. Providing an improved component indexing means which will ensure precision and repeatability in mask-to-faceplate registration during the photoscreening process. PA1 5. Providing V-groove indexing means in which the ball elements will not hang up, and which will provide positive, repeatable registration of components during manufacture.